Cognac is a type of brandy named after the town of Cognac in southwestern France, which is in the region of Nouvelle-Aquitaine. It is a renowned and protected appellation, meaning that only brandy produced in this specific region and according to certain regulations can be labeled as Cognac.

1. **Grapes:** Cognac is made from white grapes, primarily Ugni Blanc (also known as Trebbiano in Italy). Other permitted grape varieties include Colombard and Folle Blanche.

2. **Distillation:** The production of Cognac involves a double distillation process in copper pot stills. The resulting eau-de-vie (wine distillate) is then aged in oak barrels.

3. **Aging:** Cognac must be aged for a minimum period to meet specific quality designations. The aging process takes place in barrels made from French oak, and during this time, the brandy gains its characteristic flavors, colors, and aromas.

- **VS (Very Special):** Minimum aging of 2 years.

- **VSOP (Very Superior Old Pale):** Minimum aging of 4 years.

- **XO (Extra Old):** Minimum aging of 10 years (changed to 10 years from April 2018).

4. **Regions:** The Cognac region is divided into several crus or growing areas, including Grande Champagne, Petite Champagne, Borderies, Fins Bois, and Bons Bois. Grande Champagne and Petite Champagne are considered the top crus for producing high-quality Cognac.

5. **Flavor Profile:** Cognac exhibits a wide range of flavors, including fruity, floral, and spicy notes. As it ages, it develops complexity and richness. The aging process also imparts characteristics like vanilla, oak, and sometimes hints of nuttiness.

6. **Grades:** In addition to the aging designations (VS, VSOP, XO), there are prestige grades like Extra and Hors d'Âge, which represent some of the finest and oldest Cognacs.

7. **Serving:** Cognac is often enjoyed as a sipping drink, served in a tulip-shaped glass to concentrate its aromas. It can also be used in cocktails, but it is generally considered a spirit to be savored on its own.

Cognac is a symbol of luxury and craftsmanship, and its production is highly regulated to maintain the quality and authenticity of this esteemed brandy.